Perception, Ethics, and the Treatise's Own Limit
This page carries Ru-Yi's translation of Part Three, the final part, of Vasubandhu's Viṃśatikā. With the external object dismantled, a series of sharper objections follows: doesn't direct perception, at least, prove the world is real? Doesn't memory prove there was once a real object to remember? How can teachers and students understand one another, or killing carry moral weight, if there is truly nothing outside the mind? Vasubandhu answers each in turn, then closes the entire treatise with a verse of striking honesty about what his twenty verses have, and have not, actually shown.
Translation Method
The Chinese source concludes Xuánzàng's translation of Vasubandhu's Viṃśatikā (唯識二十論, T1590), with Vasubandhu's own prose commentary beneath each verse, matched with reading notes drawn from Kuījī's Viṃśatikā Śāstra Vārttika (唯識二十論述記, T1834). Kuījī closes his own commentary here with a personal note: Vasubandhu wrote this treatise, by tradition, while still on the path of preparation, not yet a fully realized bodhisattva — which is exactly why, as this page's own final verse says, the treatise ends by deferring to a buddha's own wisdom rather than claiming the last word.
Classical text is set in the left-hand column below, our English in the right. See also this site's note on translation method.
15. Does Direct Perception Prove an External Object?
Of all ways of establishing that something exists, direct perception is normally considered the most reliable — and an opponent presses exactly this: surely the plain, immediate awareness "I now perceive this object directly" proves that object is really there. Vasubandhu answers that the very structure of such awareness undercuts the claim.
諸法由量刊定有無，一切量中，現量為勝。若無外境，寧有此覺：我今現證如是境耶？此證不成。
[Objection:] Whether a thing exists is settled by a valid means of knowing it, and among all such means, direct perception is foremost. If there were no external object, how could this awareness ever arise: "I now directly perceive such an object"? [Response:] This is not valid proof.
頌曰：
「現覺如夢等， 已起現覺時，
見及境已無， 寧許有現量？」
A verse:
"Direct-perception-awareness occurs even in a dream and the like;
and by the time such an awareness has already arisen,
the seeing and its object are both already gone —
so how can this be granted as direct perception at all?"
如夢等時雖無外境，而亦得有如是現覺，餘時現覺應知亦爾，故彼引此為證不成。又若爾時有此現覺，我今現證如是色等；爾時於境能見已無，要在意識能分別故，時眼等識必已謝故。剎那論者有此覺時，色等現境亦皆已滅，如何此時許有現量？
As in a dream and the like, though there is no external object, this same kind of direct-perception-awareness can still arise — the same should be understood to hold at every other time as well, so citing this awareness as proof does not succeed. Moreover, at the very moment this awareness — "I now directly perceive such a form" — actually arises, the seeing that engaged the object is already gone, since this reflective awareness necessarily belongs to mental consciousness, and by the time mental consciousness acts, the eye-consciousness that saw has already ceased. And for those who hold that all things arise and perish moment by moment, by the time this awareness occurs, the very object it concerns has likewise already ceased — so how, at such a moment, could direct perception be granted to occur at all?
Kuījī reads this as a timing trap that catches two rival schools at once. The Sāṃmitīya school holds that the five sense-consciousnesses and mental consciousness cannot operate simultaneously — so by the time the reflective thought "I perceive this" occurs in mental consciousness, the eye-consciousness that actually did the seeing has already ceased; the "current perception" is already a memory of something no longer happening. The momentariness schools face the mirror problem: even granting simultaneous consciousnesses, the object itself, arising and perishing moment to moment, has already vanished by the time it is reflected upon. Either way, Kuījī notes, the dream comparison lands: a dream, too, produces the vivid feeling "I am now seeing this," with nothing behind it — so that feeling alone was never good evidence for an external object in the first place.
16. Memory, and Not Knowing You're Dreaming Until You Wake
If direct perception cannot prove the point, an opponent falls back on memory: surely you can only remember what you once actually, directly experienced. Vasubandhu answers this, and then meets one more attempt to use the dream comparison against him — if dreams are as empty as waking life, why don't we recognize this while dreaming, the way we recognize it once awake?
要曾現受，意識能憶，是故決定有曾受境。見此境者許為現量，由斯外境實有義成。如是要由先受後憶，證有外境理亦不成。何以故？
[Objection:] Mental consciousness can only remember what was once directly experienced — so there must certainly have been a previously experienced object, and the one who saw that object is granted direct perception of it; by this, a real external object is established. [Response:] Proving an external object this way — by prior experience followed by later memory — does not succeed either. Why?
頌曰：「如說似境識， 從此生憶念。」
A verse: "As already explained, it is the consciousness that merely appears as an object from which memory afterward arises."
如前所說，雖無外境，而眼識等似外境現。從此後位與念相應，分別意識似前境現，即說此為憶曾所受，故以後憶證先所見，實有外境，其理不成。
As already explained, though there is no external object, eye-consciousness and the rest appear as if an object were present. From this, at a later stage, a discriminating mental consciousness associated with memory arises, resembling that earlier appearance — and it is this that is called "remembering what was once experienced." So proving, by later memory, that what was earlier seen was a truly real external object does not succeed.
若如夢中雖無實境而識得起，覺時亦然。如世自知夢境非有，覺時既爾，何不自知？既不自知覺境非有，寧如夢識實境皆無？此亦非證。
[Objection:] If, as in a dream, consciousness can arise though its object is unreal, and this holds while waking too — then just as one, on waking, knows for oneself that the dream's object was unreal, why does one not likewise come to know it for oneself while awake? Since one does not, of oneself, know the waking object to be unreal, how can it be, as in a dream, that the waking object, too, is entirely absent? [Response:] This, too, is no proof.
頌曰：「未覺不能知， 夢所見非有。」
A verse: "One who has not yet awakened cannot know that what was seen in the dream does not exist."
如未覺位，不知夢境非外實有，覺時乃知。如是世間虛妄分別，串習惛熱，如在夢中，諸有所見皆非實有，未得真覺不能自知。若時得彼出世對治無分別智，乃名真覺。此後所得世間淨智現在前位，如實了知彼境非實，其義平等。
Just as, while still within the dream, one does not know that its object is not really external — one comes to know this only upon waking — so too, the world's deluded, discriminating thought, habituated over and over until it is as if fevered and clouded, is itself like being within a dream: whatever appears within it is not truly real, but until one attains true awakening, one cannot know this for oneself. Only once one attains that transmundane, non-discriminating wisdom which counteracts delusion can this be called true awakening; and once, following that, the resulting purified worldly wisdom stands before the mind, one truly and thoroughly knows those objects are unreal. In this respect, the two cases — dream, and saṃsāra itself — are exactly equal.
Kuījī draws out the parallel Vasubandhu is building with some precision: dreaming and waking are not two different kinds of experience, one empty and one real, but two moments of a single, longer sleep — the "long night" of saṃsāra itself, as scripture calls it. Just as a dream's unreality only becomes visible from the far side of waking, saṃsāra's own unreality only becomes visible from the far side of the path — first through the "true awakening" of non-discriminating wisdom on the path of seeing, and only afterward, in the purified wisdom that follows it, does one look back and know, in so many words, that what once seemed real was empty all along. Asking why we don't already know this, Kuījī says, is exactly like asking a sleeper why they don't already know their dream is a dream.
17. How Do Minds Influence Each Other Without a Shared World?
A more practical objection follows: if each being's consciousness only ever arises from its own individual continuum, with no shared external world connecting them, how can drawing near to a good or a bad influence ever actually change what one comes to believe?
若諸有情由自相續轉變差別似境識起，不由外境為所緣生，彼諸有情近善惡友、聞正邪法二識決定。既無友教，此云何成？非不得成。
[Objection:] If sentient beings' consciousnesses, which merely appear as objects, arise only from distinct transformations within their own individual continuum, and not by depending on any external object — then how can sentient beings, by drawing near to a good or a bad friend and hearing a correct or a mistaken teaching, come to have a fixed conviction of one kind or the other? Without any real friend or teaching outside the mind, how could this possibly come about? [Response:] It is not that this cannot come about.
頌曰：「展轉增上力， 二識成決定。」
A verse: "Through the reciprocal power each mind-stream exerts as a supporting condition on the other, a fixed conviction comes about in each."
以諸有情自他相續，諸識展轉為增上緣，隨其所應二識決定，謂餘相續識差別故，令餘相續差別識生，各成決定，不由外境。
The consciousnesses within the mind-streams of oneself and of others serve, reciprocally, as a supporting condition for one another, and, according to what is fitting, a fixed conviction of one kind or another results in each — that is, because the consciousness within one mind-stream is of a particular kind, it brings about, within another mind-stream, the arising of a correspondingly particular consciousness, and each thereby becomes fixed in its own conviction. None of this depends on any object external to the mind.
Kuījī is careful to specify what kind of causation is at work here: not one consciousness reaching out and directly touching another — which would smuggle a real external object straight back in — but one mind-stream serving as a supporting condition (增上緣) for changes within a separate mind-stream, the way heat can ripen fruit on a different branch without the two ever needing to merge into one thing. A teacher's own consciousness never becomes an object a student's consciousness directly grasps; rather, the teacher's presence and words condition the student's own mind-stream to generate, from its own resources, a corresponding new conviction. Nothing external is shared between them — only influence, reciprocally exerted.
18. Why Do Dream-Deeds and Waking-Deeds Ripen Differently?
Having just established that dream and waking states are, in the relevant sense, equal — both empty of a real object — an opponent presses the obvious follow-up: then why does karma clearly not treat them as equal? A dream-murder carries none of the weight of an actual one.
若如夢中，境雖無實，而識得起，覺時亦然，何緣夢覺造善惡行，愛非愛果當受不同？
[Objection:] If, as in a dream, consciousness can arise though its object is unreal, and the same holds while waking, then why is it that good and bad deeds done in a dream, and done while awake, bring about desired and undesired results that differ so greatly?
頌曰：「心由睡眠壞， 夢覺果不同。」
A verse: "Because the mind is impaired by sleep, dream-deeds and waking-deeds bear different fruit."
在夢位心，由睡眠壞，勢力羸劣。覺心不爾。故所造行，當受異熟，勝劣不同，非由外境。
The mind, in the state of dreaming, is impaired by sleep, and so its power is weak and diminished; the waking mind is not so impaired. This is why deeds done in each state come to ripen with karmic fruit of differing strength — and the difference has nothing to do with any external object.
Kuījī notes that this answer locates the difference entirely on the subject's side, not the object's — exactly where Consciousness-Only needs it to be. What determines the moral weight of an act, on this account, was never whether a real external victim stood on the other end of it, but the clarity, intention, and force of the mind that performed it. A drowsy, sleep-weakened mind produces correspondingly weak karmic seeds; a fully alert waking mind produces strong ones. The same logic, he adds, explains why deeds done in states like intoxication or delirium likewise carry diminished weight — the pattern is general, not limited to sleep alone.
19. How Is Killing Possible With No Real External Victim?
The sharpest ethical challenge follows directly: if there is no real body outside the mind at all, how can killing — or any physical harm — happen, and how can a butcher ever be guilty of a real crime? Vasubandhu's answer turns on one mind-stream's power to condition another, illustrated by a canonical story about the gravity of a purely mental act.
若唯有識無身語等，羊等云何為他所殺？若羊等死不由他害，屠者云何得殺生罪？
[Objection:] If there is only consciousness, with no real body or speech, then how can a sheep or the like ever be killed by another? And if a sheep's death does not come about through another's harming it, how can a butcher ever incur the guilt of killing a living being?
頌曰：
「由他識轉變， 有殺害事業，
如鬼等意力， 令他失念等。」
A verse:
"Through another's consciousness undergoing a transformation,
an act of killing and harming can occur —
just as, through the mental power of spirits and the like,
another being can be made to lose their memory, and so on."
如由鬼等意念勢力，令他有情失念得夢，或著魅等變異事成。具神通者意念勢力，令他夢中見種種事……如是由他識轉變故，令他違害命根事起。應知死者謂眾同分，由識變異相續斷滅。
Just as, through the mental power of spirits and the like, another being can be made to lose their memory or have a particular dream, or become possessed and behave strangely — and just as, through the mental power of one who has attained supernormal ability, another can be made to see various things within a dream — so too, through another's consciousness undergoing such a transformation, an act that violates and harms a being's life-faculty can come about. It should be understood that "death" means precisely this: that the continuity belonging to that grouping of beings is broken off, through a transformation in consciousness.
Kuījī reads "death" here in a very deliberate way: not the destruction of some external physical object, but the breaking of a mind-stream's own continuity — one consciousness-continuum, powerfully conditioned by another's karmically charged intent, simply ceasing to continue in the way it otherwise would have. He cites two illustrative examples the treatise itself gives: the arhat Mahākātyāyana's mental resolve alone causing a king to have a specific dream, and a forest-dwelling sage's mental wrath alone causing another king likewise to dream — both proof, on this account, that a mind-stream can powerfully affect another mind-stream's course with no physical contact whatsoever. Killing, on this model, is the most severe case of exactly this same mechanism.
20. The Three Forests a Sage's Wrath Emptied
Vasubandhu backs the previous verse's claim with scriptural authority: a canonical story in which the Buddha himself makes exactly this point, arguing that a purely mental act of wrath was severe enough to empty three entire forests of their inhabitants — and using this very story to establish that a mental transgression outweighs even one of body or speech.
頌曰：
「彈咤迦等空， 云何由仙忿？
意罰為大罪， 此復云何成？」
A verse:
"How, then, could the Daṇḍaka forest and the others have become empty
merely through a sage's wrath?
And how could a mental act's karmic penalty be established as the gravest of all —
how, again, could this come about?"
若不許由他識轉變增上力故他有情死，云何世尊為成意罰是大罪，故返問長者鄔波離言：「汝頗曾聞何因緣故，彈咤迦林、末蹬伽林、羯陵伽林皆空閑寂？」長者白佛言：「喬答摩！我聞由仙意憤恚故。」
If it is not accepted that another being's death can come about through the empowering influence of a transformation in someone else's consciousness, then how could the World-Honored One, in order to establish that a mental act's karmic penalty is the gravest of all, have turned the question back on the householder Upāli, asking: "Have you ever heard by what cause the Daṇḍaka, Mātaṅga, and Kaliṅga forests all became empty and desolate?" — to which the householder answered the Buddha: "Gautama, I have heard it was because of a sage's wrathful intent."
若執神鬼敬重仙人，知嫌為殺彼有情類，不但由仙意憤恚者，云何引彼成立意罰為大罪性過於身語？由此應知，但由仙忿彼有情死，理善成立。
[Objection:] Suppose it is held instead that spirits, out of reverence for the sage and sensing his displeasure, were the ones who actually killed those beings — so that it was not the sage's own wrathful intent alone that did so. [Response:] Then how could the Buddha have cited this very story to establish that a mental act's karmic penalty is graver than one of body or speech? By this, it should be understood that it is well established, on sound reasoning, that it was the sage's wrath alone that brought about those beings' deaths.
Kuījī gives the full canonical background at length: the householder Upāli was sent by his teacher, the Jain leader Jñātiputra, to debate the Buddha and win him over to the view that physical acts carry the gravest karmic weight, mental acts the least. The Buddha instead led Upāli, step by step, through a comparison — a mass execution taking many days versus a sage's momentary wrath annihilating an entire population instantly — until Upāli conceded that a mental act's power so plainly exceeded a physical one that he asked, on the spot, to become the Buddha's disciple. The three ruined forests Upāli then names — traditionally explained as places where a sage's wrath, provoked by a king's mistreatment, brought down destruction in a single night — serve the treatise as historical proof, accepted even by rival schools, that mind alone, without any physical instrument, can bring about the gravest of real effects.
21. Can One Mind Truly Know Another's?
One final objection tests Consciousness-Only from the inside: does the cognition Buddhist texts call "knowledge of another's mind" actually reach another's mind, or not — and whichever answer is given, does it not create a problem for Consciousness-Only itself?
若唯有識，諸他心智知他心不？設爾何失？若不能知，何謂他心智？若能知者，唯識應不成。雖知他心，然不如實。
[Objection:] If there is only consciousness, does the cognition of another's mind actually know another's mind, or not? [Response:] Suppose either — what is the difficulty? [Objection:] If it cannot know it, how can it be called "cognition of another's mind" at all? And if it can know it, then Consciousness-Only should not be established. [Response:] It does know another's mind — yet not exactly as that mind really is.
頌曰：
「他心智云何， 知境不如實？
如知自心智， 不知如佛境。」
A verse:
"How does the cognition of another's mind
fail to know its object exactly as it is?
The same way the cognition of one's own mind does —
neither knows the domain known only to a buddha."
諸他心智云何於境不如實知？如自心智。此自心智云何於境不如實知？由無知故。二智於境各由無知所覆蔽故，不知如佛淨智所行不可言境。此二於境不如實知，由似外境虛妄顯現故、所取能取分別未斷故。
[Objection continues:] How, exactly, does the cognition of another's mind fail to know its object as it really is? [Response:] The same way the cognition of one's own mind does. [Objection:] And how does the cognition of one's own mind fail to know its object as it really is? [Response:] Because of a remaining ignorance. Both of these cognitions are, with respect to their object, each covered over by a remaining ignorance, and so neither knows the unspeakable domain that a buddha's pure wisdom knows. Both fail to know their object exactly as it is because what they know appears, illusorily, in the guise of an external object, and because the discrimination between a grasped object and a grasping subject has not yet been fully cut off in them.
Kuījī reads Vasubandhu's answer as characteristically exact: "knowledge of another's mind" does reach past the knower's own mind-stream, in the sense that another's mental state genuinely conditions it — this is not a denial that such cognition works. What it lacks is a buddha's freedom from even the subtlest residue of the habit of grasping at subject and object as separate. Only a fully awakened buddha's mind knows another's mind without that last shadow of distortion; every other knower, however accurate in practice, still knows through a trace of the very structure the entire treatise has spent its length dismantling. Even Consciousness-Only's own explanatory apparatus, Kuījī notes, is not exempt from this qualification — which sets up exactly the honesty of the verse that closes the treatise.
22. The Treatise's Own Limit
Vasubandhu closes the entire twenty-verse treatise not with a triumphant final proof, but with a deliberate admission of its limits — a closing gesture Kuījī reads as itself an expression of the very selflessness the treatise has spent its length establishing.
唯識理趣，無邊決擇，品類差別，難度甚深，非佛誰能具廣決擇。
The principle of Consciousness-Only opens onto boundless further distinctions, vast and profound beyond easy fathoming — who, other than a buddha, could resolve them all, fully and exhaustively?
頌曰：
「我已隨自能， 略成唯識義，
此中一切種， 難思佛所行。」
A verse:
"I have, according to my own ability,
briefly established the meaning of Consciousness-Only;
beyond this, every further distinction
lies in the unthinkable domain of a buddha's own practice."
唯識理趣品類無邊，我隨自能，已略成立。餘一切種非所思議，超諸尋思所行境故。如是理趣唯佛所行，諸佛世尊於一切境及一切種智無礙故。
The distinctions within the principle of Consciousness-Only are boundless; I have, according to my own ability, only briefly established some part of it. Every further distinction lies beyond what I myself can think through or express, since it exceeds the domain that ordinary reflection can reach. Such a principle belongs to a buddha's domain alone — for the buddhas, the world-honored ones, are unobstructed with respect to every object of knowledge and every kind of wisdom concerning it.
Kuījī closes his own commentary by placing Vasubandhu's humility in context: by tradition, Vasubandhu composed this treatise while still on the path of preparation, not yet a fully realized bodhisattva, let alone a buddha — so this final deferral is not mere rhetorical modesty, but a precise statement of where the author himself stood on the path he had just spent twenty verses defending. Kuījī adds a matching note about his own work, closing his commentary with an acknowledgment that his own understanding, too, has its limits, and asking future readers' indulgence for whatever he has gotten wrong. Both author and commentator, in other words, end the treatise the same way it argues a person should meet the world: without pretending to know more than they do.
Treatise Complete
This closes Ru-Yi's translation of the Viṃśatikā in full: Vasubandhu's opening thesis that the three realms are consciousness-only; his answer to the fourfold challenge through dream, hungry ghost, and hell; the hidden intent behind scripture's own teaching that the sense-processes exist; the treatise's central argument that no atom, combined or not, with parts or without, can ever be established; and, in this closing part, the objections from perception, memory, ethics, and other minds — resolved one by one, before Vasubandhu himself steps back and hands the deepest questions to a buddha's own wisdom.
Return to the Viṃśatikā overview →